This application requests continued funding for an ongoing project examining the development of children's knowledge about and identification with social categories. My previous research has been guided by a conceptualization of changes in social knowledge as periods of transitions that may occur at any point in the lifespan. In this Phase Model of Transitions, changes in how individuals respond to new personally relevant social categories are predicted to occur in relation to changes in knowledge across 3 phases. Phase 1, Construction, is marked by open information-seeking about this new category. Phase 2, Consolidation, occurs when the individual attempts to consolidate this information into a clear set of identity-relevant conclusions. Phase 3, Integration, refers to processes that allow the individual to integrate these new identities and function more flexibly. The proposed research combines this normative developmental focus with an examination of individual differences at each phase and their consequences. Because of the complexity of this new direction, the research focuses on a single social category: gender. The proposed research is organized into 3 study sets each addressing 1 or more of the following questions: (1) What are the connections between social identity and other elements of gender development?; (2) How do individual differences in the components of gender identity, behavior, and beliefs relate to well-being?; (3) When and how do children first begin to construct their gender identities?; and (4) What role do variations in socialization/socio-cultural context play with respect to the preceding 3 research questions? The proposed studies move beyond prior research on gender identity by examining the developmental course of different components of identity and their effects on psycho-social adjustment. Although the proposed studies focus on gender, the issues being examined and the methods used will allow general principles to emerge.